Using post-consumer glass in concrete as a cement replacement
In many US cities today, there is a surplus of post-consumer glass collected by municipal recycling programs. The mixed colored glass and small pieces that often cannot be used to produce new bottles are many times sent to landfill. Recycling of larger, clear glass pieces is also currently challenged by diminished domestic bottle-making in the US. Also, as existing building facades undergo important energy retrofits, plate glass removed is often landfilled.
All of this post-consumer glass can be used to produce ground-glass pozzolan, a material that can replace cement in concrete. To achieve this, we focus on:
Diverting post-consumer glass from landfill
Producing ground-glass pozzolan from post-consumer glass
Utilizing ground-glass pozzolan as a cement replacement in concrete
Current Quantities & Uses of Glass and Other Cement Replacements
(Hover or click on chart for quantities)
Data
1. Iron and steel slag quantities (Source: USGS)
2. Slag use as cement replacement (Source: Slag Cement Association)
3. Other figures (Source: ASTM, forthcoming)
Connecting glass recycling and concrete production
1 - Pieces smaller than 3/8 inch, which can’t be separated by existing optical sorters.
2 - For more information on CRT panel glass use as a feedstock in pozzolan, see these two case studies by the NY State Pollution Prevention Institute.
Points of Diversion in Post-consumer glass Recycling
Drivers for Change
Many benefits are realized by using post-consumer ground glass pozzolan as a cement replacement. Some primary drivers for this technology are as follows:
The Ecosystem
We're currently mapping the Glass in Concrete Ecosystem, including projects, recyclers, manufacturers, and sources. Click on the points in the map below for more info.